An obvious form of ignorance is saying "bitcoin has no value", (maybe with the "intrinsic" word thrown in there), despite the manifest fact of a market price, and of a huge run up. Value is like beauty, in the eye of the beholder, and dismissing bitcoin, or CounterStrike skins, or World of Warcraft assets as valueless is ignorant.
They can't see the simple "repetition becomes truth" driver of bitcoin price, as in the longer the price is not zero, and the longer people talk between themselfs about the bitcoin price, the more real the idea that bitcoin has value becomes. This is how money is born, by a shared belief.